An external skeletal fixator is an orthopedic method for treating open or closed fractures of long tubular bones, joint stiffness, bone lengthening, and congenital malformations. An external skeletal fixator is a device that is installed outside the organ and inserts pins into the fracture to fix it and adjust the position of the pin. They are connected to the frame and secured with bolts and nuts. Fixtures have changed significantly in appearance and biomechanics over time, but the principle and function remain the same. These fixtures consist of pins or thin stainless steel wires that penetrate the skin and reach the bone. This way the broken part is fixed in the right direction. Depending on the body geometry and shape, these external skeletal fixators are available in different types such as linear, circular, and hybrid fixators. The simplest and most common type of external skeletal fixator is the linear fixator. The use of an external fixator has several advantages over other fixation methods such as stabilization of the fracture at some distance from the injury site, no need for a cast, ease of patient movement, and minimal involvement of the joint. Premature loosening of the pin is the most common complication causing pain, inflammation, and discharge from the pin tract. Although these fixators are versatile and effective treatment models, they require careful maintenance during treatment. Before deciding to use an external fixator, the patient's and pet's owner's ability to comply with postoperative care instructions should be considered. This article reviews the types of external fixators, postoperative care, and their complications.

Determination of animal unit, is one of the essential requirements for calculating the grazing capacity. For the purpose of this study, 24 breeds of sheep, significantly dominant and well distributed across the climatic regions, were identified. Two herds were selected from available flocks in each region. Randomly, 30 livestock from each herd at different ages and sex were selected and weighed in different seasons. Using cluster analysis, and on the basis of the average adult weight of races, animal unit size was determined. From the ratio of metabolic weight of sheep breeds to metabolic weight of livestock unit the conversion factor (equivalent of animal units) of each breed was calculated. Then on based of puberty weight breeds were put into three separate weight groups (light, medium and heavy). The average weight of races was found to be 50 kg. Accordingly, an animal unit for small grazing dry and non-pregnant livestock is reported as 50 kg. The conversion coefficient of 0. 7, 1 and 1. 3, were used to calculate the light, medium and heavy body size classes of animals compared to the animal unit weight respectively. The daily requirement for an animal unit estimated as 6. 80 MJ. using MAFF (1984) equation. A value of 30-80 percent must be added to the calculated value considering the topographic conditions, distance from water sources and animal daily orbit to/from resting area which requires more energy, in various climate conditions.

Lameness is a common complaint in small animal medicine. Orthopedic examination is performed by visual and manual assessment of the patient. In most cases, the affected extremity is identified, but the exact origin of that extremity remains obscure and sometimes difficult. Orthopedic examination plays an important role in determining the location of lameness, diagnosing its cause, and finding appropriate treatment. Early diagnosis of musculoskeletal problems is very important to apply appropriate treatment and preventive measures in the early stages of disease progression. Patients presenting with symptoms of musculoskeletal abnormalities should undergo a complete orthopedic examination. A systematic approach to orthopedic examination is important to assess all structures and ensure that no part is missed. The purpose of orthopedic examination is to assess the presence or absence of the disease in the patient and determine the causes of its occurrence. The orthopedic examination includes history taking, walking observation, step analysis and evaluation, and clinical examination of the patient. A history of lameness, previous diagnoses and treatments and their effects, the presence of other systemic diseases, and diet should be documented before the initiation of clinical examination. The time of onset of lameness, possible causes, and the timing of progression also help in a better diagnosis. It is very important to observe the patient walking from different directions at different speeds. Observing the patient going up and down stairs and ramps may also help. Understanding movement and gait is important for diagnosing many musculoskeletal and neurological problems. Gait analysis should be performed before any orthopedic or neurological examination. Gait analysis can help further clarify which limb is affected. Finally, an orthopedic clinical examination of the animal is performed. This article describes methods for clinical examination of the hind limb.

ameness is a common problem in small animal medicine. Since animals, especially dogs, bear most of their weight on their front legs, it seems necessary to examine the fore limb. Diagnosis and treatment of fore limb lameness are often difficult. Diagnosis of the lesion is difficult because patients usually do not show obvious pain on palpation. Investigation of the cause of lameness and the anatomical location of the lesion depends on the age, breed, and lifestyle of the animal. Therefore, a systematic orthopedic examination of the extremity is critical to ensure that all structures are assessed and no part is overlooked. An orthopedic examination includes not only a clinical examination of the patient but also an anamnesis, gait observation, stride analysis, and evaluation. First, a history of lameness, diagnosis, previous treatment, and its effectiveness, presence of other systemic conditions, and diet should be evaluated. Assessing a patient's gait on flat and sloping surfaces at different speeds can help understand which limb is lame. Studying and analyzing animal movements is considered a very important step in detecting organ damage and abnormalities. Abnormal gait that may be caused by nerve or musculoskeletal damage is therefore called lameness. It is caused by hereditary, congenital, developmental disorders, trauma, and infection of this organ. Finally, an orthopedic clinical examination of the animal is performed. The appearance of pain during the examination indicates the localization of the lesion since an orthopedic examination of the organ does not cause pain in healthy animals. First, the normal, seemingly healthy side is checked so that the animal is calm and so that individual responses to specific tests can be judged. Therefore, this article describes a method for systematic orthopedic examination of the fore limb.

External fixation by means of coaptation means using casts, splints, bandages, and slings to immobilize the injured limb. These methods if used properly approximate the shape of the limb on which they are applied and provide stable fixation of bone fragments without the need for surgical implants at the fracture site. External fixation of orthopedic injuries in veterinary medicine has significant advantages over open fixation and internal fixation. In most cases, the soft tissue and vascular damages, the risk of infection, and the cost of its use can be much lower than surgical intervention. Careful case selection is required to achieve successful treatment of fractures with external coaptation. Temporary fixation methods are usually used to prevent edema, relieve pain, reduce subsequent soft tissue damage, protect the wound from further contamination, prevent the conversion of closed fractures to open fractures, and stabilize the fractured particles in acutely injured animals. Various types of External coaptations are available in veterinary practice to provide the best external fixation of injuries. Therefore, it is essential for the practitioners in this field to have sufficient familiarity with different methods and their uses. As a general rule, external coaptation is an acceptable mode of fracture repair for animals that are younger than 1 year of age, because they heal faster. External coaptation best neutralizes flexion forces on distal fractures and requires stabilization of the joint above and below the fractured site. Therefore, coaptation has the disadvantage of prolonged immobilization of the limb, which can cause severe atrophy from "disuse atrophy" and possible "fracture disease".

Introduction: Skeletal muscles account for about 40% of the total body weight. Every year, hundreds of people lose at least part of their muscle tissue due to illness, war, and accidents. This can lead to disruption of activities such as breathing, movement, and social life. To this end, various therapeutic strategies such as medication therapy, cell therapy and tissue transplantation have been used or studied in muscle regeneration. However, there is no effective and well-defined clinical approach for treatment of muscle injuries and the severity of muscle injuries increase with age in most cases. Therefore, investigation for finding new and effective clinical approach for muscle regeneration is one of the most important issues in basic and clinical researches. Tissue engineering is considered as one of the promising and newest approach for skeletal muscle tissue regeneration and provides an appropriate model for personalized medicine and basic researches that can be used in personalized medicine and basic research. Besides biomaterials and cells, inducing factors are another element of tissue engineering. These factors influence epigenetic mechanisms and signaling pathway, thereby inducing proliferation, differentiation, and migration of cells used in muscle tissue engineering, and accelerates muscle formation in vitro. Recently, small molecules have been used as alternatives to growth factors or along with other inducing factors in muscle tissue engineering. Since they do not induce an immune reaction, penetrate easily to the cells and have a specific molecular target, therefore they have attracted much attention as the cost-effective inducing factors in tissue engineering. Conclusion: Taken together, the effective small molecules in muscle tissue engineering can be used with different biomaterial conditions (e. g. hydrogel, decellularized tissue, and synthetic scaffolds) in both in vivo and in vitro, resulting to production of cost effective and highly efficient engineered muscle tissues that help to achieve therapeutical goals of muscle tissue engineering. Herein, we describe tissue engineering and review the small molecules used in skeletal muscle tissue engineering.